Title: Evolution of optical signatures in western Lake Erie as related to HAB
formation and senescence
Authors: Tim Moore1, Tom Johengen2, Colleen Mouw2, Steve Ruberg4, Jim
Sullivan5, Mike Twardowski5, Danna Palladino4, Nicole Stockley5, Dack Stuart2,
Angela Yu2
1 University of New Hampshire
2 Cooperative Institute for Limnology and Ecosystems Research
3 Michigan Technological University
4 NOAA/GLERL
5 WET Labs
Abstract: In 2014, a harmful algal bloom (HAB) began in western Lake Erie in late
July and continued into October. Over this time period, a variety of instrumentation
utilized on cruises captured the optical temporal and spatial variability of the bloom.
Hyperspectral radiometry was measured from late June through early November at
NOAA sites, and in mid-August a multi-day field survey yielded detailed
measurements of the horizontal and vertical optical structure of the water in the
western basin. These measurements included hyperspectral radiometry,
microscopic holographic imagery, absorption and scattering characteristics of the
water column. We observed water types from HAB-free waters of the Detroit River
plume, to floating Microcystis mats near Maumee Bay. We also observed a transition
from Microcystis- to Planktothrix-dominated waters transiting east into the central
basin. Based on these data sets, an optical picture of the evolution of the water over
the span of the bloom has emerged, which contain many interesting aspects of the
environmental variability of the basin over space and time. These results have
important implications for remote sensing algorithms and applications.